Association of ectopic posterior pituitary and anterior pituitary hypoplasia with absence of the left internal carotid

Neural Crest Cell Failure as Embryogenesis for Fusiform Aneurysm of the Anterior Communicating Artery: Case Report and Review of the Literature

BACKGROUND

Pure fusiform aneurysms of the anterior communicating artery (AcomA) are rare. We report a unique case of a patient with an AComA fusiform aneurysm in the setting of several unusual cranial neurocristopathies, including a hypoplastic internal carotid artery (ICA), persistent craniopharyngeal canal, transsphenoidal encephalocele, and ectopic, duplicated pituitary gland. We also review the literature on cranial base neurocristopathies and AComA fusiform aneurysms.

CASE DESCRIPTION

This 46-year-old patient had a history of short stature, osteoporosis, obesity, cleft lip, decreased libido, congenital left eye blindness, headaches, and chronic nasal congestion. Magnetic resonance imaging revealed a 25 × 25 × 33 mm heterogenous soft tissue mass with an ectopic pituitary gland extending transsphenoidally and a duplicated pituitary stalk. A hormone panel revealed undetectable insulin-like growth factor 1 and growth hormone, central hypogonadism, and elevated prolactin. Before presentation, computed tomography angiography (CTA) had revealed a congenitally hypoplastic right ICA and 4.7 × 10.7 mm fusiform aneurysm of the AComA. Digital subtraction angiography confirmed stable morphology after 9 years. Nonoperative management of aneurysm and cephalocele was elected, with repeat CTA in 1 year.

CONCLUSIONS

This case provides evidence that inherent arterial wall defects can contribute to fusiform aneurysm formation in the AComA. We propose that small AComA fusiform aneurysms without sclerotic or symptomatic features can be safely observed by describing the longest reported conservative management for this type of aneurysm. A high degree of suspicion for cerebrovascular anomalies should be maintained in patients who present with cranial neurocristopathy.

Structural malformations of the brain, eye, and pituitary gland in PHACE syndrome

PHACE syndrome is the association of segmental facial hemangiomas with congenital arterial, brain, cardiac, and ocular anomalies. Structural brain malformations affect 41-52% of PHACE patients and can be associated with focal neurologic deficits, developmental delays, and/or intellectual disability. To better characterize the spectrum of structural brain and other intracranial anomalies in PHACE syndrome, MRI scans of the head/neck were retrospectively reviewed in 55 patients from the PHACE Syndrome International Clinical Registry and Genetic Repository. All registry patients with a diagnosis of definite PHACE syndrome who had MRI scans of satisfactory quality were included. Of 55 patients, 34 (62%) demonstrated ≥1 non-vascular intracranial anomaly; structural brain malformations were present in 19 (35%). There was no difference in the prevalence of brain anomalies between genders. Brain anomalies were more likely in patients with S1 and/or S2 distribution of facial hemangioma. The most common structural brain defects were cerebellar hypoplasia (25%) and fourth ventricle abnormalities (13%). Dandy-Walker complex and malformations of cortical development were present in 9% and 7%, respectively. Extra-axial findings such as pituitary anomalies (18%) and intracranial hemangiomas (18%) were also observed. Six patients (11%) had anomalies of the globes or optic nerve/chiasm detectable on MRI. Brain malformations comprise a diverse group of structural developmental anomalies that are common in patients with PHACE syndrome. Along with brain malformations, numerous abnormalities of the pituitary, meninges, and globes were observed, highlighting the need for careful radiologic assessment of these structures in the neuroimaging workup for PHACE syndrome.

A Novel Mutation in OTX2 Causes Combined Pituitary Hormone Deficiency, Bilateral Microphthalmia, and Agenesis of the Left Internal Carotid Artery

BACKGROUND

Mutations in OTX2 cause hypopituitarism, ranging from isolated growth hormone deficiency to combined pituitary hormone deficiency (CPHD), which are commonly detected in association with severe eye abnormalities, including anophthalmia or microphthalmia. Pituitary phenotypes of OTX2 mutation carriers are highly variable; however, ACTH deficiency during the neonatal period is not common in previous reports.

OBJECTIVE

We report a novel missense OTX2 (R89P) mutation in a CPHD patient with severe hypoglycemia in the neonatal period due to ACTH deficiency, bilateral microphthalmia, and agenesis of the left internal carotid artery (ICA).

RESULTS

We identified a novel heterozygous mutation in OTX2 (c.266G>C, p.R89P). R89P OTX2 showed markedly reduced transcriptional activity of HESX1 and POU1F1 reporters compared with wild-type OTX2. A dominant negative effect was noted only in the transcription analysis with POU1F1 promoter. Electrophoretic mobility shift assay experiments showed that R89P OTX2 abrogated DNA-binding ability.

CONCLUSION

OTX2 mutations can cause ACTH deficiency in the neonatal period. Our study also shows that OTX2 mutations are associated with agenesis of the ICA. To the best of our knowledge, this is the first report of a transcription factor gene mutation, which was identified due to agenesis of the ICA of a patient with CPHD. This study extends our understanding of the phenotypic features, molecular mechanism, and developmental course associated with mutations in OTX2.

Agenesis of internal carotid artery associated with isolated growth hormone deficiency: a case report and literature review

BACKGROUND

Agenesis of the internal carotid artery (ICA) is a rare congenital abnormality, sporadically reported to be associated with a combined congenital hypopituitarism. Nevertheless, only a few cases have been extensively described, and none of these have been characterized by an isolated growth hormone (GH) deficiency.

CASE PRESENTATION

Here, we describe a 17-year old boy referred to our hospital for fatigue, decreased muscle strength and severe headache reported after the cessation of rhGH treatment for a GH deficiency diagnosed at the age of 2 years and 3 months. Magnetic resonance imaging (MRI) showed an adenohypophyseal hypoplasia with a lack of posterior pituitary hyperintensity, whereas MRI angiography indicated the absence of a normal flow void in the left ICA. Endocrinological tests confirmed the GH deficiency (GH peak after growth-hormone-releasing hormone (GHRH) + arginine: 2.42 ng/mL) with a very low IGF-I value (31 ng/mL) and normal function of other pituitary axes.

CONCLUSION

To the best of our knowledge this is the first confirmed case of an isolated GH deficiency in a patient with ICA agenesis. The presence of an isolated pituitary deficit is unlike to be considered only as an effect of hemodynamic mechanism, suggesting a role for genetic factor(s) as a common cause of these two rare birth defects. Further studies could clarify this issue and the underlying mechanisms to better understand the etiopathogenetic characteristics of this disorder.

Unilateral agenesis of internal carotid artery associated with congenital combined pituitary hormone deficiency and pituitary stalk interruption without HESX1, LHX4 or OTX2 mutation: a case report

Agenesis of internal carotid artery (ICA) is an unusual finding in subjects with congenital Combined Pituitary hormone deficiency (CPHD) with only nine cases being reported to date but to our best knowledge none of them was genetically investigated. A 10-years old girl presented with severe growth failure (height 103 cm) with substantial bone age delay (3 years). She had no history of perinatal insults or familial CPHD. There was no evidence of mental retardation or craniofacial dysmorphism or ophtalmological abnormalities. She was first diagnosed with GH and TSH deficiency. Cerebral magnetic resonance imaging (MRI) showed hypoplastic anterior pituitary, flat sella turcica, absent pituitary stalk with ectopic posterior pituitary as well as agenesis of the left ICA and the left carotid canal. Genomic analysis of pituitary transcription factor HESX1, LHX4 and OTX2 showed no mutations. Treatment with GH and thyroxine was started. The patient remained free of neurovascular symptoms for 5 years but she presented at the age of 15 years with delayed puberty related to an evolving gonadotropin deficiency. ICA agenesis associated with CPHD is unusual and is often asymptomatic in children. Since the CPHD with pituitary stalk interruption cannot be due to HESX1, LHX4 or OTX2 mutation in our case, other pathogenetic mechanisms may be responsible for CPHD associated with unilateral ICA agenesis.

Agenesis of internal carotid artery and hypopituitarism: case report and review of literature

CONTEXT

Agenesis of the internal carotid artery and hypoplasia of the internal carotid artery are rare congenital abnormalities, involving less than 0.01% of the general population. Congenital hypopituitarism is also a rare condition; thus, the association of the two entities is unlikely to be casual. We describe one pediatric case of agenesis of the internal carotid artery with hypopituitarism and review other known cases.

EVIDENCE ACQUISITION AND SYNTHESIS

In this brief clinical case seminar, we summarize the current understanding of this association based on a MEDLINE search of all peer-reviewed publications (original articles and reviews) on this topic between 1980 and 2011. We found nine other cases, mainly diagnosed during childhood. Defects of pituitary function varied among cases; in four, midline anomalies were present.

CONCLUSION

There are two theories that are not mutually exclusive to explain the association of congenital vascular malformation and pituitary hypoplasia with hypopituitarism: the first involves hemodynamic mechanisms, and the second, complex neural-crest differentiation and/or migration disorders. Whatever the real physiopathological mechanism responsible for this condition, it could be considered as a new clinical entity.

Agenesis of the internal carotid artery and hypogenesis of the pituitary gland: cause, consequence or coincidence?

The CT and MR imaging findings in a case of unilateral agenesis of the internal carotid artery and hypogenesis of the pituitary gland are described in a child with congenital hypopituitarism. The embryological pathogenesis is discussed.

Agenesis of the internal carotid artery and congenital pituitary hypoplasia: proposal of a cause of congenital hypopituitarism

We describe a patient with microphallus without pigmentation and multiple pituitary hormone deficiencies. The left internal carotid artery and carotid canal were absent and the pituitary gland and sella turcica showed hypoplasia on MRI and magnetic resonance angiography. The internal carotid artery develops in the 4th embryonic week, while the pituitary primordium develops in the 3rd to 4th week. This suggests a possible relationship between internal carotid artery and congenital hypopituitarism. However, there is bilateral blood supply to the hypophysis via the superior and inferior hypophysial arteries, so it is unknown why pituitary hypoplasia may arise from blocking the unilateral blood supply.

CONCLUSION

Disruption of internal carotid artery perfusion may lead to pituitary hypoplasia with congenital hypopituitarism as a new disease entity in humans.

Hypothalamic-pituitary dysfunction associated with Moyamoya disease in children

Moyamoya disease is a rare cerebral vascular disease that results in narrowing of the vessels of the circle of Willis and the formation of a network of collateral vessels at the base of the brain for compensatory perfusion. Moyamoya disease has the highest incidence during the first decade of life, and children present most frequently with transient ischemic attacks. We present two cases of Moyamoya disease in children with associated hypothalamic-pituitary dysfunction. Both children presented to the endocrinologist for decreased growth velocity. One child had hypothyroidism and both had growth hormone deficiency. A review of the literature reveals a few isolated case reports of hypothalamic-pituitary dysfunction occurring with Moyamoya disease and with other states of cerebral vascular insufficiency. We suggest that children with compromise of cerebral vascular perfusion be monitored closely for clinical signs and symptoms of hypothalamic-pituitary dysfunction.